Entorhinal cortex lesions are a common experimental paradigm to study memory function and neural plasticity after hippocampal deafferentation. The long term consequences of such lesions are of particular interest both in the context of these models and because pathological changes of Alzheimer's disease destroy entorhinal cortex projection neurons. We used stereological counting techniques to assess the structural integrity of the hippocampal formation 0.5-28 months after entorhinal lesion in the rhesus monkey. Surprisingly, 18-28 months after lesion the number of CA3 neurons was decreased by 57%, while neuron numbers in other subfields did not change. These results suggest that delayed transsynaptic neural degeneration can occur long after brain injury.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0304-3940(95)11879-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Evaluating conversion from mild cognitive impairment to Alzheimer's disease with structural MRI: a machine learning study.
Brain Commun
January 2025
Neuropsychiatry Laboratory, Department of Clinical Neuroscience and Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome 00179, Italy.
Alzheimer's disease is a disabling neurodegenerative disorder for which no effective treatment currently exists. To predict the diagnosis of Alzheimer's disease could be crucial for patients' outcome, but current Alzheimer's disease biomarkers are invasive, time consuming or expensive. Thus, developing MRI-based computational methods for Alzheimer's disease early diagnosis would be essential to narrow down the phenotypic measures predictive of cognitive decline.
View Article and Find Full Text PDFImpaired spatial coding of the hippocampus in a dentate gyrus hypoplasia mouse model.
Proc Natl Acad Sci U S A
February 2025
Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218.
The hippocampal dentate gyrus (DG) is thought to orthogonalize inputs from the entorhinal cortex (pattern separation) and relay this information to the CA3 region. In turn, attractor dynamics in CA3 perform a pattern completion or error correction operation before sending its output to CA1. In a mouse model of congenital hypoplasia of the DG, a deficiency in the (Wls) gene, specifically in cells expressing , which targets neuronal progenitors, led to an almost total absence of dentate granule cells and modestly impaired performance in spatial tasks.
View Article and Find Full Text PDFVolume electron microscopy reveals unique laminar synaptic characteristics in the human entorhinal cortex.
Elife
January 2025
Instituto Cajal (CSIC), Madrid, Spain.
The entorhinal cortex (EC) plays a pivotal role in memory function and spatial navigation, connecting the hippocampus with the neocortex. The EC integrates a wide range of cortical and subcortical inputs, but its synaptic organization in the human brain is largely unknown. We used volume electron microscopy to perform a 3D analysis of the microanatomical features of synapses in all layers of the medial EC (MEC) from the human brain.
View Article and Find Full Text PDFPermanent tactile sensory loss reduces neuronal activity in the amygdala and ventral hippocampus and alters anxiety-like behaviors.
Behav Brain Res
January 2025
Laboratorio de Neurociencias, Facultad de Psicología, Universidad de Colima, Colima, Mexico 28040. Electronic address:
Tactile information from the whiskers (vibrissae) travels through the somatosensory cortex to the entorhinal cortex and the hippocampus, influencing development and psychological well-being. The lack of whiskers affects cognitive functions, spatial memory, neuronal firing, spatial mapping, and neurogenesis in the dorsal hippocampus. Recent studies underline the importance of tactile experiences in emotional health, noting that while tactile stimuli modulate the dorsal hippocampus, the effects of tactile deprivation on anxiety-like behaviors and neural activity in regions like the ventral hippocampus and amygdala are less understood.
View Article and Find Full Text PDFThe role of oscillations in grid cells' toroidal topology.
PLoS Comput Biol
January 2025
Kavli Institute for Systems Neuroscience and Centre for Algorithms in the Cortex, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Persistent homology applied to the activity of grid cells in the Medial Entorhinal Cortex suggests that this activity lies on a toroidal manifold. By analyzing real data and a simple model, we show that neural oscillations play a key role in the appearance of this toroidal topology. To quantitatively monitor how changes in spike trains influence the topology of the data, we first define a robust measure for the degree of toroidality of a dataset.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!